StarCraft II notoriously stores user settings, replays, and cache variables in your Documents folder, not the install folder. If your Documents folder is synced to OneDrive or owned by a different user account (common after a Windows update), the game cannot write the Variables.txt file needed to finish "Preparing Game Data."
Do not reinstall the game—that rarely fixes this issue, because the problem is cache-related, not the game files themselves. starcraft 2 preparing game data exclusive
Have you encountered the "Preparing Game Data" loop? Let us know in the comments if the cache clear worked for you. StarCraft II notoriously stores user settings, replays, and
Repeat this for %LocalAppdata% and %AppData% to ensure a clean slate. StarCraft II notoriously stores user settings